Method for repairing a torn meniscus

ABSTRACT

A method for repairing tears in fibrocartilage and soft tissue. The clip has a pair of opposed legs formed of rigid biodegradable material. Each leg has at least one barb for easily penetrating the cartilage and soft tissue, and for opposing withdrawal from it. The legs are interconnected by a flexible section that is also biodegradable. The instrument for applying these clips has a pair of opposed jaws, each with at least one notch for holding the barbs of the clip. The jaws are biased apart in a normally open position and are interconnected to an actuating handle. The instrument further includes a device which closes the jaws when the handles are moved a first way relative to one another and opens them when the handles are moved the other way.

This is a continuation of co-pending application Ser. No. 07/672,895,filed on Mar. 21, 1991 now abandoned, which is a continuation of pendingU.S. application Ser. No. 07/511,445, filed Apr. 18, 1990 now U.S. Pat.No. 5,002,562, which is a continuation of application Ser. No.07/201,841 filed Jun. 3, 1988, now abandoned.

FIELD OF INVENTION

This invention relates to a method for inserting a clip used to repairmenisci and soft tissue.

BACKGROUND OF INVENTION

Tears in fibrocartilage and soft tissue, especially peripheral meniscaltears, are reatively difficult to repair. Typically, a tear in thevascular region of the meniscus is sutured using arthroscopictechniques. The instrument may be inserted through small incisions whichserve as anterior knee portals. Sutures on long needles are then passedthrough a meniscal repair instrument and through the meniscus. Anincision is made in the back of the knee to permit the surgeon to pullthe needles and suture out, and to tie the suture over the posteriorjoint capsule. This technique reapproximates the torn edges of themeniscus and allows for healing.

Although effective, this repair technique requires a surgeon skilled inarthroscopic meniscal repair. The technique is also relatively timeconsuming and more invasive than it need be, as it requires a second,posterior incision that increases the risk of infection andneurovascular damage. As a result, few surgeons will attempt meniscalrepair, choosing instead to simply remove the damaged portion of themeniscus. The problem with this approach is that meniscal removal cancause increased stress on the articular cartilage, which may then leadto degenerative arthritis.

Surgical clips are often easier to insert than sutures. However, mostclips are not biodegradable, and occasionally a second operation must beperformed to remove the clip once the tissue has healed. Anotherdisadvantage of these clips is that they are not well suited formeniscal and soft tissue repair, as they are typically metallic,relatively large, and may protrude from the tissue and cause jointirritation. Thus, although arthroscopic clips can be inserted through asingle incision, they have typically not been used for repair ofperipheral meniscal tears nor for arthroscopic repair of soft tissue.

SUMMARY OF INVENTION

It is therefore an object of this invention to provide a method forinserted arthroscopic clip for operative arthroscopic repair of menisciand soft tissue.

It is a further object of this invention to provide a method forinserting an arthroscopic clip which allows a surgeon not trained inmeniscal repair to reapproximate torn meniscal tissue.

It is a further object of this invention to provide a method and anarthroscopic clip which decrease risk of neurovascular damage to thepatient.

It is a further object of this invention to provide a method and anarthroscopic clip which decrease operative time, by facilitating theoperative procedure.

It is a further object of this invention to provide a method and anarthroscopic clip that do not require a second operation to remove theclip.

It is a further object of this invention to provide a method and anarthroscopic surgical clip with legs that remain buried in the tissueand do not irritate surrounding tissue.

This invention results from the realization that arthroscopic surgicalclips for repairing tears in menisci and soft tissue can be improveddramatically by providing a biodegradable clip with rigid, barbed legsinterconnected by a flexible section that is inserted in the tissue withan arthroscopic tool and anchors itself in the tissue to approximate thetear.

This invention features an arthroscopic clip and insertion tool forrepair of tears in fibrocartilage and soft tissue. The clip has a pairof opposed legs formed of rigid biodegradable material interconnected bya flexible, biodegradable section. Each leg has at least one barb thatallows the clip to be easily inserted into the tissue being repaired butkeeps the clip from working out of the tissue. The legs of the clip arepreferably curved inwardly toward each other, and each leg preferablyhas more than one barb on its outer side. A preferred material for thelegs is a polyglycolic acid polymer.

The arthroscopic instrument for applying the barbed arthroscopic clipshas a pair of opposed jaws that are preferably offset to allow them tooverlap when closed. Each jaw has at least one notch for holding thebarbs of the clip. These specialized jaws tightly hold the clips inplace until they are fully inserted, which allows the physician to placethem in exactly the right position and to exactly the right depth beforethey are released. The instrument includes a biasing means forseparating the jaws in a normally open position, which is the positionin which the jaws remain as the clip insertion begins. The jaws areconnected to a handle by a member such as a tubular member. Theinstrument also includes means for closing the jaws when the two handlemembers are moved one way relative to one another and opening the jawswhen the handles are moved another way.

Preferably, the actuating handle is normally biased open, and the meansfor closing the jaws closes them when the handle members are squeezedtogether and opens them when the handle members are spread apart. Themeans for closing may include means for pulling the jaws together as thehandle members are moved. The jaws may be disposed at an angle to thetubular member to facilitate clip insertion. Additionally, the tips ofthe jaws are preferably sharpened to facilitate clip insertion.

Preferably, the instrument further includes means for releasing the clipfrom the jaws so it stays in place when the jaws are opened. The meansfor releasing may include means for releasably holding at least one barbof the clip, and may further include means for selectively releasing themeans for releasably holding the barb from the barb. Means for actuatingthe means for selectively releasing, which may include an actuatingmember or switch on the handle of the instrument, are also preferablyincluded.

In use, the clip is placed in the jaws with the barbs in the jawnotches. This holds the clip tightly in place as it is inserted. Toinsert the clip, the physician begins pushing the jaws into the tissue,squeezing the handle members at the same time. The sharpened tips of thejaws pierce the tissue and, as it is inserted, the legs are movedtogether. Preferably, the jaws of the instrument overlap when they arecompletely closed. This overlapping causes the legs of the clip tooverlap when it is completely inserted in the tissue. The switch on thehandle then is moved upward to release the clip from the jaws. The barbson the clip legs then hold the clip in position once the jaws are openedup and pulled away from the clip. When the instrument is removed fromthe tissue, the clip remains with its legs completely embedded withinthe tissue with only the flexible, non-irritating interconnecting memberprotruding from the tissue surface. Since the clip is biodegradable, itslowly dissolves as the tissue heals itself, and there is no need for asecond operation to remove the clips.

DISCLOSURE OF PREFERRED EMBODIMENT

Other objects, features, and advantages will occur from the followingdescription of a preferred embodiment and the accompanying drawings, inwhich:

FIG. 1 is an elevational view of an arthroscopic clip for repairingtears in cartilage and soft tissue according to this invention;

FIG. 2 is a diagram of a meniscular tear reapproximated by three of theclips of FIG. 1;

FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2;

FIG. 4A is an axonometric view of an arthroscopic tool for inserting theclip of FIG. 1 according to this invention;

FIG. 4B is a close-up view of the jaws of the tool of FIG. 4A;

FIG. 4C is a partial cross-sectional view of the handle, trigger andactuating member of the tool of FIG. 4A;

FIG. 4D is a diagrammatic view of an angled jaw for the tool of FIG. 4A;

FIG. 5 is an elevational view of an alternative arthroscopic clipaccording to this invention; and

FIG. 6 is an elevational view of an alternative to the jaws of FIG. 4A.

An arthroscopic clip for arthroscopic repair of tears in fibrocartilageand soft tissue which is especially useful for meniscal repair accordingto this invention may be accomplished by providing a clip with a pair ofopposed legs formed of a rigid biodegradable material. Each leg has atleast one barb that allows the clip to easily penetrate the tissue beingrepaired and oppose withdrawal from it. The legs are interconnected by aflexible, non-irritating biodegradable section that allows the clip tobend.

Preferably, the legs of the clip are curved inwardly toward each other,and the barbs are on the outside of the legs. The barbs mayalternatively be on the insides of the legs. These legs are preferablymade from a polyglycolic acid polymer. The flexible interconnectingsection can be formed of suture material or another relatively soft,flexible material that allows the clip to bend as it is inserted so thatthe clip can overlap inside the tissue being approximated. The clip isideally suited for reapproximating peripheral meniscal tears.

The arthroscopic instrument for applying the clips includes a pair ofopposed jaws each having at least one notch for holding the barbs of theclip. This allows the clip to be tightly held in place in the jaws untilit is completely inserted in the tissue being repaired. The jaws arebiased apart in a normally open position, and they are attached to thehandle by a tubular member. The actuating handle has opposed handlemembers and is also connected to the jaws by means such as a pair ofwires or an actuating member which close the jaws when the handle issqueezed. The instrument may have jaws preset at different angles tofurther facilitate insertion of the clip. The jaws may also havesharpened tips to facilitate insertion. In addition, the jaws arepreferably offset so they overlap when closed, so that the legs of theclip overlap inside the tissue to better approximate the torn tissue.

There is shown in FIG. 1 one embodiment of an arthroscopic clip 10 forrepair of tears in cartilage and soft tissue according to thisinvention. The clip is especially useful for repairing peripheralmeniscal tears, partial or small rotator cuff tears, labrum tears inshoulder arthroscopy, and retinacular repair after patellardislocations. The clip has barbed legs 12 and 14 with barbs 18 and 20,and 22 and 24, respectively. Legs 12 and 14 are formed of a rigidbiodegradable material which may be a polyglycolic acid polymer. Legs 12and 14 are interconnected by biodegradable, flexible, non-irritatingsection 16 which may be a suture material. Section 16 bends to allow thelegs to move in toward each other and overlap as they are pushed intothe tissue. Once inserted, the clips hold the tissue in place longenough for it to heal, and slowly dissolve so the patient does not haveto undergo a second operation for clip removal.

Peripheral meniscal tear 32, FIG. 2, is a relatively small tear that isconsidered repairable. Because of the problems to date with meniscalsurgery, portion 94 of meniscus 30, encompassed by the dashed lines, hasoften been removed when a peripheral tear is found. Since meniscalremoval may cause increased stress on the articular cartilage andsecondarily lead to degenerative arthritis, repair is far superior toremoval. By using clips such as clips 34, 35, and 38, the meniscus canbe successfully repaired with a single operative procedure.

Clip 34 is shown embedded in meniscus 30 in FIG. 3. Clip 34 includesbarbed legs 38 and 40 interconnected by flexible section 36. Wheninserted, legs 38 and 40 overlap, which causes the legs to approximatethe tissue and minimize gap 32 through which fibrous tissue will formand thus further enhance healing. When the clip is inserted as shown,only the soft connecting portion 36 protrudes from the tissue and isexposed to the articular cartilage. Since this soft material does notirritate the surrounding articular cartilage, the patient does not needto have the joint rigidly immobilized for a long period of time. This isan additional advantage of the arthroscopic clip according to thisinvention.

The arthroscopic instrument for applying the barbed clips is shown inFIG. 4A. Instrument 50 includes notched jaws 64 and 66 made of springsteel formed to keep them in a normally open position. Tubular member 60interconnects jaws 64 and 66 to handle 62. Pin, bolt, or rivet 79attaches the jaws to member 60. Handle 62 includes handle members 52 and54 that are normally biased apart by spring 56. Hinge pin 58 allowshandle member 54 to move toward handle member 52 as the handle issqueezed.

The action of the opening and closing of the jaws of the instrument canbe more clearly seen in FIG. 4B. Jaws 64 and 66 are formed from springsteel member 68. Wires 53 and 55 are attached to jaws 66 and 64 atpoints 84 and 82, respectively, and are separated by running themthrough channels 78 and 80 attached to the inside of tubular member 60.Wires 53 and 55 are pulled taut when the handle member is squeezed. Thiscauses the jaws to close. The clip is held firmly in place in the jawsas it is inserted in the tissue by providing notches 70 and 72 in jaw 64and notches 74 and 76 in jaw 66 that are shaped to hold the clip barbs.Insertion is further facilitated by sharpened tips 65 and 67, whichpierce the tissue just ahead of tips of the clip.

In operation, a clip such as clip 10, FIG. 1, is inserted in the openjaws 64 and 66. Barbs 18 and 20 fit in slots 70 and 72. Barbs 22 and 24fit in slots 74 and 76. The tip of the clip is located very close totips 65 and 67 of jaws 64 and 66, respectively. When the jaws are inplace against the two sides of the torn tissue being repaired, theinstrument is moved forward and handle 62 is squeezed. This pushes thelegs of the clip into the tissue and moves the legs together as the clipis inserted. The jaws of the instrument are preferably made slightlyoffset as shown so that they overlap when completely closed. In thatcase, when the clip is completely inserted its legs are crossed as theyare in FIG. 3.

Whether the clip legs are crossed or not, they are completely embeddedwithin the tissue. This is advantageous because the rigid leg materialcould irritate the tissue surrounding the area being repaired as theprior art surgical clips have done in other parts of the body. Once theclip is inserted, the jaws are backed out of the tissue and theinstrument is removed from the patient. The instrument can then be usedto insert another clip in the torn tissue.

The operation of the handle member to open and close the jaws is shownmore clearly in FIG. 4C. Tubular member 60 is attached to handle member52 by rivet 57. Wires 53 and 55 are attached to handle member 54, whichpivots on pin 58 when handles 52 and 54 are squeezed together. As handle54 moves toward handle 52, it pulls wires 53 and 55 back, which pullsthe jaws together and causes them to close. Since the jaws are normallybiased apart, when the handle members are released, wires 53 and 55 arerelaxed, and the jaws open to release the clip. Wire 108 is attached tosliding switch 92, which pulls wire 108 when it is slid in the directionof the arrow to release the clip as fully explained below in conjunctionwith FIG. 6.

An alternative way of forming the jaws of the arthroscopic instrument isshown in FIG. 4D. Jaws 64a and 66a are formed at a 30 degree angle totubular member 60a. Pin, rivet, or bolt 79a attaches the jaws to thetubular member.

Preferably, at least three insertion tools with jaws at different anglesare available. One with jaws aligned with the tubular member, one withjaws turned down at approximately 15 degrees, and one with jaws turneddown at approximately 30 degrees. This allows the physician to place theclip exactly as desired, depending on the location of the tear,utilizing the same arthroscopic portal during repair.

Another way of forming the arthroscopic clip is shown in FIG. 5. Clip10a includes barbed legs 12a and 14a formed of a rigid biodegradablematerial, for example a polyglycolic acid polymer. Barbs 18a, 20a, 22aand 24a are fully embedded within the tissue being repaired and do notinterfere with joint movement. Tip barbs 96 and 98 allow clip 10a togrip the meniscus so it stays embedded when the jaws are pulled back andout of the patient. This is more clearly shown in FIG. 6. Flexiblesection 81 is made an intergral part of clip 10a, but is preferably madefrom a relatively soft, flexible biodegradable material which allows theclip to bend as it is inserted so the legs can be fully embedded in thetissue. A preferred material of the flexible clip is 2.0 Dexon suture.Since interconnecting section 81 is the only section of the clip that isexposed from the meniscus after the clip is inserted, the soft materialalso provides a clip that is less irritating to the surroundingcartilage than the typical stiff or metallic clips would be and whichwould not be able to be used intra-articularly.

Another way of forming the jaws to ensure proper insertion of clip 10ais shown in FIG. 6. Jaws 100 and 102 are formed to hold the barbs ofclip 10a while the clip is being inserted and to release the clip afterinsertion so that it remains in place embedded in the meniscus.Barb-holding members 104 are spring steel members with smallindentations shaped to fit and hold the clip barbs. Wire 106 is attachedto members 104. Wire 108 connects wire 106 to switch 92, FIG. 4A.

When clip 10a is fully inserted in the meniscus, the physician operatesswitch or lever 92. Switch operation pulls on wire 108, FIG. 6, which inturn pulls wire 106. Wire 106 is attached to the underside of members104. As wire 106 is pulled tight, it pulls members 104 down away fromclip 10a. This frees the barbs and leaves them embedded in the meniscus.Insertion barbs 96 and 98 also may be included to help hold clip 10a inplace by gripping the tissue just enough to allow clip 10a to separatefrom jaws 102 and 100 as the jaws are opened and backed out of themeniscus. In conjunction with members 104, insertion barbs 96 and 98prevent clip 10a from not properly separating from the instrument as itis removed from the mensicus.

Although specific features of the invention are shown in some drawingsand not others, this is for convenience only as each feature may becombined with any or all of the other features in accordance with theinvention.

Other embodiments will occur to those skilled in the art and are withinthe following claims:

What is claimed is:
 1. A method for repairing a tear in the meniscuscomprising:providing a staple having a pair of legs joined together by aflexible suture material; inserting the staple into the meniscus so thesuture material overlies the tear; and bending the staple legs inwardlytowards each other.
 2. A method as in claim 1, wherein said staple legsand said suture material are biodegradable.
 3. A method of repairing atear in the meniscus comprising:providing a staple having a pair of legsjoined together by a flexible material; and inserting the staple intothe meniscus so the flexible material overlies the tear.
 4. The methodof claim 3, wherein the staple legs are composed of a biodegradablematerial.
 5. The method of claim 4, wherein the flexible material is abiodegradable suture material.
 6. The method of claim 3, wherein saidlegs are composed of a rigid material.
 7. The method of claim 6 whereineach said leg includes at least one tissue retaining barb.
 8. The methodof repairing a tear in the meniscus comprising:providing an instrumenthaving a pair of opposed jaws; placing a staple having a pair of legsjoined by a suture material in said jaws so each staple leg is receivedin the notch formed in each jaw; inserting the instrument in the body toposition the jaws over the tear; squeezing said handles of theinstrument to close the jaws; and releasing the staple from the jaws sothat the flexible material overlies the tear.
 9. The method of claim 8,wherein the staple is composed of biodegradable material.
 10. The methodof claim 9, wherein each staple leg has an integral tissue retainingbarb and said barb is positioned in the notch of the jaw.
 11. The methodof claim 10, wherein the step of releasing the staple comprises pullinga wire to actuate barb holding members to disengage the instrument fromthe barbs.